The motto of gamblers-united.com is “No more betting when the house has an abusive edge.”
Which raises a question: How big must an edge be to be “abusive”?
Some gambling experts pinpoint the number at 2%, which is low enough to seem reasonable while high enough that it doesn’t limit gaming options. Without digging too deeply into the mathematics just now, this threshold allows access to many common casino games while making it easy to steer clear of the worst games on the casino floor.
To aid us in that decision-making process, it may be useful to consider two important maxims for casino mathematics. The first: All casino games are designed to give the house an advantage.
That’s right – the odds are against you going into any game. The games are rigged. With that in mind, though, it is worthwhile first to consider the four common casino games where the player can occasionally have an advantage due to changing conditions:
- Blackjack – using basic strategy, counting cards, and adjusting one’s play as dictated by the count.
- Video poker – assuming proper game selection (certain Deuces Wild machines, for example) and adherence to the correct strategy table for that game.
- Live poker – in which the skill of the other players plays a major role in setting the conditions of the game.
- Sports betting – if you can pick winners at greater than about a 53% rate, you can bet with an edge.
What these games have in common, of course, is a skill component – there are points in the course of gameplay when the gambler can have a meaningful effect on the game by his or her actions.
On the other hand, while you can get an edge through your actions in these games, that edge is not large and is likely to be short-lived.
The second maxim gives some insight into choosing “better” bets: The easier a wager is to understand, the higher the house advantage. This was quoted in an episode of Sex and the City set in Atlantic City, and it can be used as a rough guide to separate the good bets from the bad.
For example, the rules for the basic pass/don’t pass wager in craps are somewhat complicated, so we expect that it would have a low house edge–and it does: 1.41% for Pass, 1.31% for Don’t Pass. Free odds, where available, can take this edge down further. On the other hand, the “Any 7″ bet is extremely simple to understand – you’re betting on whether or not the next roll of the dice will be a 7–and its 16.67% house edge is very high.
Baccarat is another example of a game with complex rules and a low house edge, provided that you avoid the Tie bet, which is easy to understand (bet on the likelihood that the two hands are tied after the complicated rules for standing and drawing are played out) and has a casino edge of 14%.
By the same token, American roulette (house advantage 5.26% on almost every bet) and keno (house edge typically at least 20%) are very easy games to understand and to play–pick some numbers, and see if they come up on a spinning wheel or a computerized random number generator.
2% actually winds up as a pretty broad margin – blackjack, craps, and baccarat all have primary wagers which come in under this limit. The key is avoiding the side bets, which invariably have a much higher advantage for the house. Even roulette can be playable, if you’re playing a single-zero (European) wheel with the en prison rule on even-money bets and confine your action to those wagers; the house edge there is about 1.35%.
Keno, on the other hand, may be beyond rescue. While it would certainly be easy to devise a keno wager with a house edge under 2%, there would be little incentive for a casino to offer such a bet. Keno is not typically a game where the house can compensate for a low edge with high bet volume, which is the key to how a casino can profit with low-edge games.
Mark Bollman is Professor of Mathematics and Chair of the Department of Mathematics and Computer Science at Albion College in Michigan. Read more about the mathematics of gambling in his book Basic Gambling Mathematics: The Numbers Behind The Neon, available from CRC Press or at amazon.com.